Abstract In this study, we analyze different methods for the generation of homogenized few-group cross sections (XS) using continuous-energy Monte Carlo codes Serpent 2.1.29 and MCU–PTR for full-core diffusion calculation of small-size light water research reactors. Few-group reaction cross sections, scattering matrices and diffusion coefficients generated in an infinite lattice model with and without B1-leakage correction of spectra, and in full-scale 3D core calculations, are compared. Few-group XS are used in the TIGRIS diffusion nodal simulator to calculate the simplified cores with IRT-3 M fuel and a light water reflector. Special attention is paid to the impact of diffusion coefficients on the results of diffusion calculations. We compare the following different methods for the generation of diffusion coefficients: the usual “out-scatter” approximation, the transport correction for hydrogen implemented in Serpent, and the migration method implemented in MCU–PTR.

中文翻译：

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研究堆全堆芯扩散计算与使用 Serpent 和 MCU-PTR 生成的少数组横截面的比较

摘要 在本研究中，我们分析了使用连续能量蒙特卡罗代码 Serpent 2.1.29 和 MCU-PTR 生成均匀少群横截面 (XS) 的不同方法，用于小尺寸轻水研究的全核扩散计算反应堆。比较了在具有和不具有光谱的 B1 泄漏校正和全尺寸 3D 核心计算的无限晶格模型中生成的少数群反应截面、散射矩阵和扩散系数。在 TIGRIS 扩散节点模拟器中使用少群 XS 来计算具有 IRT-3 M 燃料和轻水反射器的简化堆芯。特别注意扩散系数对扩散计算结果的影响。我们比较了以下不同的生成扩散系数的方法：